This invention relates to a method for the production of 3,4,5-trithiatricyclo[5.2.1.0.sup.2,6 ]decanes and the 3,4,5-trithiapolycyclo derivatives thereof.
The interaction of sulfur with organic compounds has been known for many years to generally result in complex polysulfide compounds. More specifically, and recently, it was shown in U.S. Pat. No. 3,586,700 that ammonia and certain other organic amines could catalyze the interaction of sulfur with certain bicyclo[2.2.1]hept-2-ene compounds to produce a novel class of 3,4,5-trithiatricyclo[5.2.1.0.sup.2,6 ]decane compounds. It was also shown that this catalytic reaction occurs only in the presence of certain highly polar organic solvents and that the sulfuration occurs only across the double bond in the bicyclo[2.2.1]hept-2-ene ring structure.
U.S. Pat. No. 4,033,982 also discloses a method for the preparation of the subject compounds. That method requires the use of a phenol and a base and can be carried out in the absence or presence of an inert organic solvent. It is disclosed that the base is employed in order to form, in the presence of the phenol, a metal phenoxide. Sodium sulfide is listed as a representative base.
U.S. Pat. No. 3,882,031 discloses a method of sulfurizing bicyclo[2.2.1]hept-2-enes for use as lubricant additives. The sulfurization is carried out in the absence of a solvent or in the presence of a non-polar solvent. Sulfide ions are described as a less-than-preferred catalyst, and the method typically employs a solubilizing agent to assist in increasing the proportion of oil-soluble constituents in the product. Further, pyridine is listed as an amine catalyst.
It would be highly desirable to possess a high yield process for the preparation of 3,4,5-trithiatricyclodecanes and derivatives thereof which, in addition to providing higher yields than the methods of the prior art, did not require an amine catalyst, a phenol, or a solubilizing agent.